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Summary

This script calculates catch by OHI region using landings data provided by NOAA>

Data

Reference: [citation for source data; website, literature, contact information. Version of data (if relevant). Screenshots if a series of menus had to be navigated to obtain the data.]

Downloaded: April 3, 2019

Description: Commercial fish landings by statistical area

Time range: 1996-2017. Data provided annually

Format: Excel spreadsheet


Data Cleaning

Cleaning the raw data a bit by fixing column names and turning stat_area numeric.

## # A tibble: 6 x 6
##    year stat_area species                      pounds stock_id stock       
##   <dbl>     <dbl> <chr>                         <dbl> <chr>    <chr>       
## 1  1996         0 CONFIDENTIAL SPECIES       11517161 <NA>     <NA>        
## 2  1996       462 COD                           11827 CODGMSS  GOM Cod     
## 3  1996       462 CUSK                           1065 <NA>     <NA>        
## 4  1996       462 FLOUNDER, AMERICAN PLAICE…    21191 PLAGMMA  Plaice      
## 5  1996       462 FLOUNDER, WITCH / GRAY SO…     5496 WITGMMA  Witch Floun…
## 6  1996       462 HADDOCK                         296 HADGM    GOM Haddock

Spatial data

Since the data is provided by statistical landing area, we can use this information to infer what OHI region’s encompass or overlap with these areas. We have downloaded the shapefile for Statistical Areas from this public FTP NOAA site.

Statistical areas

Load in the statistical areas and add area of each polygon as a column.

Overlay statistical areas with our regions to find what ones are in our area

Calculate proportion of each statistical area in our OHI regions. For statistical areas that overlap with OHI regions, we can use proportional area overlap to adjust catch. We assume that catch is evenly distributed across each statistical area.

Catch per OHI region

Now we calculate the total catch per species and year for each of the OHI regions.

First let’s filter the catch data to just the statistical areas in our region. We don’t care about the catch outside of these statistical areas.

## # A tibble: 20 x 8
##    species stock_id stock rgn_id  year rgn_name          catch display_name
##    <chr>   <chr>    <chr>  <int> <dbl> <fct>             <dbl> <chr>       
##  1 ALEWIFE <NA>     <NA>       3  1998 Gulf of Maine    2.63e3 ALEWIFE     
##  2 ALEWIFE <NA>     <NA>       3  1999 Gulf of Maine    4.34e1 ALEWIFE     
##  3 ALEWIFE <NA>     <NA>       3  2000 Gulf of Maine    2.41e2 ALEWIFE     
##  4 ALEWIFE <NA>     <NA>       3  2003 Gulf of Maine    4.66e1 ALEWIFE     
##  5 ALEWIFE <NA>     <NA>       3  2006 Gulf of Maine    0.     ALEWIFE     
##  6 ALEWIFE <NA>     <NA>       3  2007 Gulf of Maine    0.     ALEWIFE     
##  7 ALEWIFE <NA>     <NA>       4  2012 Mid-Atlantic Bi… 5.62e2 ALEWIFE     
##  8 ALEWIFE <NA>     <NA>       4  2013 Mid-Atlantic Bi… 6.40e3 ALEWIFE     
##  9 ALEWIFE <NA>     <NA>       4  2014 Mid-Atlantic Bi… 0.     ALEWIFE     
## 10 ALEWIFE <NA>     <NA>       4  2015 Mid-Atlantic Bi… 0.     ALEWIFE     
## 11 ALEWIFE <NA>     <NA>       4  2016 Mid-Atlantic Bi… 0.     ALEWIFE     
## 12 ALEWIFE <NA>     <NA>       4  2017 Mid-Atlantic Bi… 0.     ALEWIFE     
## 13 ALEWIFE <NA>     <NA>       5  2013 Connecticut      2.62e3 ALEWIFE     
## 14 ALEWIFE <NA>     <NA>       5  2014 Connecticut      0.     ALEWIFE     
## 15 ALEWIFE <NA>     <NA>       5  2016 Connecticut      0.     ALEWIFE     
## 16 ALEWIFE <NA>     <NA>       5  2017 Connecticut      0.     ALEWIFE     
## 17 ALEWIFE <NA>     <NA>       6  1998 Maine            5.39e2 ALEWIFE     
## 18 ALEWIFE <NA>     <NA>       6  1999 Maine            8.90e0 ALEWIFE     
## 19 ALEWIFE <NA>     <NA>       6  2000 Maine            4.94e1 ALEWIFE     
## 20 ALEWIFE <NA>     <NA>       6  2003 Maine            9.56e0 ALEWIFE

Visualize catch by region

Mapping just one species - Winter Flounder, George’s Bank

Gapfill

The data shared with us includes records of 0 catch. But there is still missing data. As an example, let’s look at ALEWIFE.

##  [1] 1998 1999 2000 2003 2006 2007 2012 2013 2014 2015 2016 2017

Ok clearly we are missing data for 2001, 2002, 04-05, 2008-11. We don’t know if these are 0’s or missing data. We need to gapfill this missing data. When a species/state combination has missing data for a year, we can not assume it has a catch of 0. Since we calculate a rolling average of catch, NAs will remain as NA’s and the average will rely on just one or two years of catch. This is done to account for any wild fluctuations in catch year to year.

Let’s look at total regional catch for each species (not stock)

Clearly atlantic herring is making up the majority of catch! Atlantic herring is primarily a bait fishery, so we need to account for that since this goal is only measuring catch meant for human consumption. We adjust for this below.

Remove non-food catch

Some of these species are harvested for food as well as other markets like pet food or bait. We want to make sure this goal captures catch meant for human consumption. We have data from NOAA that identifies the amount of catch per species, state and year meant for food, bait, and other markets. This data was cleaned in prop_catch_food_bait.Rmd.